Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Over an inch of rain is coming in during the day on Wednesday. We've already gotten so much moisture that it may just be absorbed into an already-soaked snowpack with little additional activity, but we're not quite sure. Avoid traveling on or below big, steep slopes, cornices, cliffs, or any snow-covered rocky terrain while the rain keeps pouring down. 

Avalanche problems

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    Glide avalanches, wet slabs, cornice failures are all on the table. Slopes that haven't yet failed since the big warmup on Friday and the subsequent 6+ inches of rain may fail as heavy rain comes down on Wednesday. That being said, a lot of avalanche activity has already occurred with initial and subsequent wetting, so we don't suspect a large round of natural avalanche activity to take place.

    All forms of wet avalanches, aside from wet loose, tend to be highly unpredictable. Even if natural avalanches are not likely, it's still hard to tell when and where they'll fail, so stack the odds in your favor and avoid steep terrain and traveling below suspect slopes while the rain is pouring down and just after. The same goes for human-triggered avalanches, but it's just not a day to be out in the steeps.  There's a good chance that any slides that come down won't be inconsequential. You can expect large to very large avalanches, with thick, heavy, wet, chunky snow and it'll probably kill you if you're caught.  

    Example photo: Large glide cracks are open, and have run, in many areas throughout the zone. Don't travel beneath the gaping cracks.

    Photo: Lee Lazzara

Avalanche Discussion

Days of rain have saturated the snowpack. Temperatures have been above freezing at 5000ft since Friday. In that time, the Heather Meadows weather station has reported over 6 inches of water. At the start of the week, we had better visibility and could see the aftermath of some of the avalanche activity from the weekend and before. Several D2 (large) and D3 (very large) avalanches were seen, some with streaks of dirt showing, indicating the avalanche gouged all the way to the ground. 

Lower elevations are melting out quickly. Most avalanche activity has probably subsided there, but beware of gullies and large overhead paths that come from higher elevations where an avalanche may fail and travel to lower elevations. 

If you do head to the mountains, bring many waterproof layers, expect thick, wet snow, swollen and open creeks and water bodies, and far less coverage than the last time you were out.

Regions covered